This invention relates to packaging of primary articles such as cans and bottles in multiple packaged cartons and is more particularly concerned with feeding such articles from an infeed and for loading into a carton.
More particularly, this invention relates to a device for grouping together a plurality of articles from an infeed stream at an infeed end of a packaging machine and is particularly useful for grouping together a plurality of cans or bottles in a multiple packaging machine.
A majority of known packaging machines are dedicated machines which construct only one type of carton. Therefore, modern bottling plants are required to use a plurality of packaging machines to package different carton types, each machine taking up considerable floor space and being expensive to both purchase and operate.
A limited number of packaging machines are capable of packaging different sizes of one carton, for example, six, eight or twelve bottles of a wraparound carton. All such machines require adjustment when switching from one size or type of carton to another. This adjustment includes the manual removal of all of the cartons within the packaging machine and possibly the mechanical adjustment of components in the machine. During this changeover period, which can be thirty minutes or more, a machine cannot be used (known as downtime), which is an expensive delay in a bottling plant. Such a delay may even result in downtime for the entire bottling line, not just the packaging machine, if problems arise during the changeover procedure.
In a known spacer and conveying mechanism disclosed in EP 0 126 553, or EP 0 708 028, a series of spacer elements are spaced apart at fixed locations on the endless chains, each spacer element being configured to engage a plurality of articles from an infeed stream of articles and convey those articles downstream of the machine. The spacing between each spacer element corresponds to the spacing between successive groups of articles. GB A 974 995 discloses a grouping mechanism for grouping articles into package units which comprises a first pair of chains which have lugs spaced apart at fixed intervals for engaging articles at an infeed end of the apparatus. The pair of chains are mounted on opposite sides of a pair of fixed support plates which together with the lugs cooperate to divide the array of articles at the infeed into groups of fixed separation and propel the groups towards a second pair of chains also having lugs spaced apart at fixed intervals. The second pair of chains has a greater downstream velocity compared to the first pair of chains. The upstream article of a group of articles is engaged by a lug of the second pair of chains thereby forcing the groups of articles forward at a greater speed than that determined by the first pair of chains.